class RDoc::Markup::ToRdoc

def accept_blank_line(blank_line)
  @res << "\n"
end

def accept_block_quote(block_quote)
  @indent += 2
  block_quote.parts.each do |part|
    @prefix = '> '
    part.accept self
  end
  @indent -= 2
end

def accept_heading(heading)
  use_prefix or @res << ' ' * @indent
  @res << @headings[heading.level][0]
  @res << attributes(heading.text)
  @res << @headings[heading.level][1]
  @res << "\n"
end

def accept_indented_paragraph(paragraph)
  @indent += paragraph.indent
  text = paragraph.text @hard_break
  wrap attributes text
  @indent -= paragraph.indent
end

def accept_list_end(list)
  @list_index.pop
  @list_type.pop
  @list_width.pop
end

def accept_list_item_end(list_item)
  width = case @list_type.last
          when :BULLET then
            2
          when :NOTE, :LABEL then
            if @prefix then
              @res << @prefix.strip
              @prefix = nil
            end
            @res << "\n"
            2
          else
            bullet = @list_index.last.to_s
            @list_index[-1] = @list_index.last.succ
            bullet.length + 2
          end
  @indent -= width
end

def accept_list_item_start(list_item)
  type = @list_type.last
  case type
  when :NOTE, :LABEL then
    stripped_labels = Array(list_item.label).map do |label|
      attributes(label).strip
    end
    bullets = case type
    when :NOTE
      stripped_labels.map { |b| "#{b}::" }
    when :LABEL
      stripped_labels.map { |b| "[#{b}]" }
    end
    bullets = bullets.join("\n")
    bullets << "\n" unless stripped_labels.empty?
    @prefix = ' ' * @indent
    @indent += 2
    @prefix << bullets + (' ' * @indent)
  else
    bullet = type == :BULLET ? '*' :  @list_index.last.to_s + '.'
    @prefix = (' ' * @indent) + bullet.ljust(bullet.length + 1)
    width = bullet.length + 1
    @indent += width
  end
end

def accept_list_start(list)
  case list.type
  when :BULLET then
    @list_index << nil
    @list_width << 1
  when :LABEL, :NOTE then
    @list_index << nil
    @list_width << 2
  when :LALPHA then
    @list_index << 'a'
    @list_width << list.items.length.to_s.length
  when :NUMBER then
    @list_index << 1
    @list_width << list.items.length.to_s.length
  when :UALPHA then
    @list_index << 'A'
    @list_width << list.items.length.to_s.length
  else
    raise RDoc::Error, "invalid list type #{list.type}"
  end
  @list_type << list.type
end

def accept_paragraph(paragraph)
  text = paragraph.text @hard_break
  wrap attributes text
end

def accept_raw(raw)
  @res << raw.parts.join("\n")
end

def accept_rule(rule)
  use_prefix or @res << ' ' * @indent
  @res << '-' * (@width - @indent)
  @res << "\n"
end

def accept_table(header, body, aligns)
  header = header.map { |h| attributes h }
  body = body.map { |row| row.map { |t| attributes t } }
  widths = header.zip(*body).map do |cols|
    cols.compact.map { |col| calculate_text_width(col) }.max
  end
  aligns = aligns.map do |a|
    case a
    when nil, :center
      :center
    when :left
      :ljust
    when :right
      :rjust
    end
  end
  @res << header.zip(widths, aligns).map do |h, w, a|
    extra_width = h.size - calculate_text_width(h)
    h.__send__(a, w + extra_width)
  end.join("|").rstrip << "\n"
  @res << widths.map {|w| "-" * w }.join("|") << "\n"
  body.each do |row|
    @res << widths.zip(aligns).each_with_index.map do |(w, a), i|
      t = row[i] || ""
      extra_width = t.size - calculate_text_width(t)
      t.__send__(a, w + extra_width)
    end.join("|").rstrip << "\n"
  end
end

def accept_verbatim(verbatim)
  indent = ' ' * (@indent + 2)
  verbatim.parts.each do |part|
    @res << indent unless part == "\n"
    @res << part
  end
  @res << "\n"
end

def add_text(text)
  emit_inline(text)
end

def attributes(text)
  handle_inline(text)
end

def calculate_text_width(text)
  text.size
end

def emit_inline(text)
  @inline_output << text
end

def end_accepting
  @res.join
end

def handle_BOLD(target)
  on(:BOLD)
  super
  off(:BOLD)
end

def handle_BOLD_WORD(word)
  on(:BOLD)
  super
  off(:BOLD)
end

def handle_EM(target)
  on(:EM)
  super
  off(:EM)
end

def handle_EM_WORD(word)
  on(:EM)
  super
  off(:EM)
end

def handle_HARD_BREAK
  add_text("\n")
end

def handle_PLAIN_TEXT(text)
  add_text(text)
end

def handle_REGEXP_HANDLING_TEXT(text)
  add_text(text)
end

def handle_STRIKE(target)
  on(:STRIKE)
  super
  off(:STRIKE)
end

def handle_TIDYLINK(label_part, url)
  super
  add_text("( #{url} )")
end

def handle_TT(code)
  on(:TT)
  super
  off(:TT)
end

def handle_inline(text, initial_attributes = [])
  @attributes = Hash.new(0)
  initial_attributes.each { |attr| on(attr) }
  out = @inline_output = +''
  super(text)
  @inline_output = nil
  out
end

def handle_regexp_SUPPRESSED_CROSSREF(text)
  text.sub('\\', '')
end

def initialize(markup = nil)
  super nil, markup
  @markup.add_regexp_handling(/\\\S/, :SUPPRESSED_CROSSREF)
  @width = 78
  @headings = DEFAULT_HEADINGS.dup
  @hard_break = "\n"
end

def off(attr)
  @attributes[attr] -= 1
  @attributes.delete(attr) if @attributes[attr] == 0
end

def on(attr)
  @attributes[attr] += 1
end

def start_accepting
  @res = [""]
  @indent = 0
  @prefix = nil
  @list_index = []
  @list_type  = []
  @list_width = []
end

def use_prefix
  prefix, @prefix = @prefix, nil
  @res << prefix if prefix
  prefix
end

def wrap(text)
  return unless text && !text.empty?
  text_len = @width - @indent
  text_len = 20 if text_len < 20
  next_prefix = ' ' * @indent
  prefix = @prefix || next_prefix
  @prefix = nil
  text.scan(/\G(?:([^ \n]{#{text_len}})(?=[^ \n])|(.{1,#{text_len}})(?:[ \n]|\z))/) do
    @res << prefix << ($1 || $2) << "\n"
    prefix = next_prefix
  end
end